The present invention generally relates to motion control apparatus and in particular brakes. Specifically, the present invention relates to brakes suitable for use with a track to brake motion such as linear motion and, more specifically, relates to linear motion brakes utilizing low voltage direct current for actuation.
The popularity of linear motion devices in the machine tool, semiconductor, and medical industries has been increasing as the result of their ability to move a load in a linear movement direction to a position with extreme accuracy and at very high speeds. However, problems have been encountered in stopping or holding linear loads especially in the event of a power outage. Specifically, as movement and positioning of the load is dependent upon current being supplied to the linear motor, loads carried by linear motion devices will move under gravitational and/or inertia forces in the event that current is interrupted to the linear motor such as the result of a failure. This problem is also enhanced in linear motion devices because of the use of high performance linear bearings, which minimize sliding friction. Prior workers have devised a brake that cures the above deficiencies and that works with remarkable reliability and precision, see U.S. Pat. No. 6,460,678 to Henk et al., and U.S. Pat. No. 7,124,861 to Maher. The aforementioned art utilizes primarily fluid pressure for actuation. Many applications for linear devices do not have suitable sources of fluid pressure. However, electrical power, especially in low voltage, is readily available.
Mechatronics technology (the combination of mechanical engineering, electronic engineering and computing) is replacing traditional power methods that designers have relied upon for decades. In order to capture market share in this dynamic field, many companies are investing in products that perform the tasks of their pneumatic and hydraulic counterparts but with electrified power sources.
Thus, a need exists for a brake for stopping linearly moving loads and especially for use with linear motion devices and particularly for use in stopping linearly moving loads that includes electric actuation as a mode of operation.
Further, there is a need for electromechanical products that meet or exceed the performance characteristics of traditional pneumatic or hydraulic devices at marketable costs.